Storage service quality assurance method and device

The invention discloses a storage service quality assurance method and device. The method comprises the following steps of: reading system performance upper limit information; monitoring system load; and if the system load is lower than a preset percentage of a system performance upper limit, reducing a performance lower limit of each volume to ensure that the total of the performance lower limits of all the volumes reaches the preset percentage of the system performance upper limit. 本发明公开了种存储服务质量保障方法及装置，该方法包括：读取系统性能上限信息；监测系统负载；若系统负载低于系统性能上限的预设百分比，提高每个卷的性能下限，使所有卷的性能下限的总和达到系统性能上限的预设百分比。该方法实现提高存储性能。